Santos A. Cardona, an Army dog handler involved in the abuse of Iraqi prisoners at Abu Ghraib, was determined to continue fighting in America's overseas battles to erase the stain of his assault conviction, his family members said.

Those closest to him said his passion for doing what he loved in the service of his country led him to try to return to Iraq in 2006, but the military brought him home after his planned deployment was publicized. Late last year, Cardona, 34, got his chance to rejoin the fight.

He traveled to Afghanistan as a government contractor, using a German shepherd to search for improvised explosive devices and weapons stockpiles. On Saturday, Cardona and his dog, Zomie, were killed when his military convoy hit a roadside bomb, according to Cardona's employer and his family.

Cardona's death was a violent end to a quest for redemption. His loved ones said he undertook one last year at war to earn money for his young daughter, show the military that he was good at his job, and dispel the cloud caused by photographs from Abu Ghraib that circled the globe.

"He wanted to prove that he had nothing to hide, and his way of dealing with that was to go back to war," said Steven Acevedo, Cardona's uncle and close friend. "He very much believed his job was important, but he was resentful that his president and that his government had turned their back on him and tried to use him as a scapegoat. He was really torn up about that."

Cardona and his tan Belgian Malinois, Duco, were shown in photographs of detainee abuse that surfaced publicly in 2004. The most notable image showed Duco growling at a cowering, naked detainee.

Cardona argued he was ordered to have Duco intimidate high-value detainees at the behest of senior officers -- claims supported by court testimony and military records -- and jurors acquitted him of all but one assault charge. Cardona was ecstatic after receiving a verdict that spared him jail time and allowed him to stay in the Army.

But staying in the Army did not mean the legacy of Abu Ghraib would disappear. After his blocked attempt to return to Iraq in 2006, he worked at the Army's dog kennels at Fort Bragg, N.C. Demoted as part of his sentence and finding he was unable to sign up for the five more years it would have taken to earn a full military retirement pension, Cardona was honorably discharged on Sept. 29, 2007, according to Army records.

Though Cardona always believed he had done nothing wrong at Abu Ghraib, he carried a silent anger at those who ordered his actions but never were held to account, family members said.

"I know that the accusations and the trial tore him up," said Heather Ashby, the mother of Cardona's 9-year-old daughter, Keelyn. "Emotionally, it was a huge drain on him. I don't think he ever wanted to be remembered like that, and I know he was angry that people who were giving orders didn't pay a price or defend what happened and instead let the lower enlisted take a hit."

Easygoing, sometimes goofy, Cardona was dedicated to the life of a soldier. He joined the Army at age 17 in 1993 -- needing his father's signature to do so -- and envisioned a military career. He met Ashby, also a military police soldier, while the two were stationed in Germany in the late 1990s, and Keelyn was born in 1999. It was then that Cardona fell in love with dog handling and was sent to Kosovo, Afghanistan and Iraq, where he used his dogs on patrols to sniff out bombs and provide security.

He so loved his working dogs that he adopted them after they were retired from service. Duco, now 12 years old, lives with Keelyn and Ashby in Florida.